The role of capnography in endoscopy patients undergoing nurse-administered propofol sedation: a randomized study

Abstract

Objective. Standard benzodiazepine/opioid cocktail has proven inferior to propofol sedation during complicated endoscopic procedures and in low-tolerance patients. Propofol is a short-acting hypnotic with a potential risk of respiratory depression at levels of moderate to deep sedation. The existing literature on capnography for endoscopy patients sedated with nurse-administered propofol sedation (NAPS) is limited. Can the addition of capnography to standard monitoring during endoscopy with NAPS reduce the number, duration, and level of hypoxia. Materials and methods. This study was a randomized controlled trial with an intervention group (capnography) and a control group (without capnography). Eligible subjects were consecutive patients for endoscopy at Gentofte Hospital compliant with the criteria of NAPS. Results. Five hundred and forty patients, 263 with capnography and 277 without capnography, were included in the analysis. The number and total duration of hypoxia was reduced by 39.3% and 21.1% in the intervention group compared to the control group (p > 0.05). No differences in actions taken against insufficient respiration were found. Changes in end-tidal carbon dioxide (R = 0.177, p-value < 0.001) and respiratory rate (R = 0.092, p-value < 0.001) were correlated to oxygen saturation (SpO₂) up to 36 s prior to changes in SpO₂. Conclusions. Capnography seems to reduce the number and duration of hypoxia in NAPS patients (p > 0.05). Capnography is able to detect insufficient respiration that may lead to hypoxia prior to changes in pulse oximetry. However, due to a limited clinical benefit and additional costs associated with capnography, we do not find capnography necessary during the use of NAPS.

Key Words::

• capnography
• endoscopy
• endoscopy-general
• NAPS
• propofol
• sedation

Acknowledgments

There are no additional contributors except the authors.

Author contributions

Charlotte Slagelse: First author, manuscript, study development and completion, statistical analysis. Peter Vilmann: manuscript revision, study development and completion. Pernille Hornslet: manuscript revision, study development and completion. Henrik L. Jørgensen: Statistical analysis and manuscript revision. Tina I. Horsted: Anesthesiological assistance, manuscript revision.

Place of conduction

Copenhagen University Hospital Gentofte, Niels Andersens vej 65, 2900 Hellerup, Denmark.

Grant support list

Public funding: The Danish Agency for Science, Technology and Innovation has supported the project with 72,170.00 DKK as a scholarship of seven months. Private funding: “Snedkermester Sophus Jacobsen og hustrus Astrid Jacobsens Fond” has supported the project with 20,000 DKK as part of a one-year scholarship.

Declaration of interest: Vicare Medical has provided one out of three capnographic monitors (Phillips MP20) and part of the specialized bite blocks/nasal cannulas (Smart CapnoLine Guardian^™ ) was provided by the Danish company Medidane. The funders had no role in study design, data collection, and analysis, decision to publish, or preparation of the manuscript. Study participants have been informed of the disclosure of interest. None of the authors have further to disclosure.